Samenvatting

A method for directly analysing the nickel content of organic samples by flame atomic absorption is validated. This method is developed to bypass the conventional preparation step for aqueous atomic absorption, which is microwave digestion. The working range of the method is 0 – 30 ppm. The limits of detection (LOD) and quantification (LOQ) of the instrument are determined to be 0.35 ppm and 0.71 ppm respectively. The relative standard deviation (RSD) of the repeatability parameter is 0.32%, while the RSD of the reproducibility varies between 2% and 6%, with the application of a successive dilution leading to an increase in reproducibility RSD. The mean recovery of the method is 100.8%, leading to a bias of 0.8%. Successive dilutions cause a greater deviation from the 100% recovery baseline than singular dilutions. Precipitation occurs when high cobalt samples are diluted 10x. Measuring these samples immediately after dilution gives a nickel value that is comparable to the reference method.